Geldanamycins: Potent Hsp90 Inhibitors with Significant Potential in Cancer Therapy.

Geldanamycin, an ansa-macrolide composed of a rigid benzoquinone ring and an aliphatic ansa-bridge, was isolated from Streptomyces hygroscopicus. Geldanamycin is a potent heat shock protein inhibitor with remarkable antiproliferative activity. However, it shows pronounced hepatotoxicity in animal models and unfavorable pharmacokinetic properties. Four geldanamycin analogs have progressed through various phases of clinical trials, but none have yet completed clinical evaluation or received FDA approval. To enhance the efficacy of these Hsp90 inhibitors, strategies such as prodrug approaches or nanocarrier delivery systems could be employed to minimize systemic and organ toxicity. Furthermore, exploring new drug combinations may help overcome resistance, potentially improving therapeutic outcomes. This review discusses the mechanism of action of geldanamycin, its pharmacokinetic properties, and the various approaches employed to alleviate its toxicity and maximize its clinical efficacy. The main focus is on those derivatives that have progressed to clinical trials or that have shown important in vivo activity in preclinical models.

A randomized, double-blind, placebo-controlled study to evaluate the benefits of a standardized Nigella sativa oil containing 5% thymoquinone in reducing the symptoms of seasonal allergy.

BACKGROUND: Allergic rhinitis (AR) or seasonal allergy characterized by sneezing, nasal congestion, nasal itching, and nasal discharge, triggered by immune reactions to environmental allergens. Present day customers also monitor the personal improvements in the area of Evidence-Based natural medicines/supplements. METHODS: A randomized, double-blind, placebo-controlled study was conducted on 65 participants aged 18 to 60 years having 2 or more allergic symptoms like sneezing, rhinorrhoea, nasal obstruction, and nasal itching for a cumulative period greater than 1 hour per day. The study participants received a capsule of NSO (250 mg) with 2.5 mg piperine (BioPerine) as a bioavailability enhancer or a placebo, twice a day, after food for 15 days. The primary objectives were evaluated by mean change in Total Nasal Symptom Score and the duration of AR symptoms per day from baseline to Day 15. Secondary endpoints were changes in Total Ocular Symptoms Score, AR symptom frequency and severity, serum Immunoglobulin E levels, and Patient Global Impression of Change scale. Adverse events were monitored throughout the study. RESULTS: Sixty-five patients were enrolled and all of them completed the study, N = 33 in NSO and N = 32 in placebo. A significant reduction in Total Nasal Symptom Score and Total Ocular Symptoms Score was observed in the NSO group compared to the placebo, highlighting the potential of NSO in alleviating AR symptoms. The episodes of AR symptoms per day and the frequency of symptoms in 24 hours reduced significantly in 15 days in both groups, but the extent of improvement was significantly higher in NSO compared to placebo. Improvement in Patient Global Impression of Change was also significantly better in NSO compared to the placebo. Serum Immunoglobulin E levels decreased in NSO but were not significantly different from placebo. No clinically significant changes were observed in vital signs, liver and renal function, lipid profile, hematology, fasting blood sugar, or urine analysis at the end of the study. CONCLUSION: The result of the study demonstrates that NSO 250 mg with 2.5 mg piperine is an effective and well-tolerated supplement for the management of AR symptoms.

The anti-neoplastic impact of thymoquinone from Nigella sativa on small cell lung cancer: In vitro and in vivo investigations.

PURPOSE: Malignant and aggressive, small cell lung cancer (SCLC) constitutes about 15% of all diagnosed lung cancer cases. With primary therapeutic options such as chemotherapy accompanied by debilitating side effects, interest has been soaring in the therapeutic competencies of herbs. The pharmacological driving force behind the beneficial properties of Nigella sativa is the quinone, thymoquinone (TQ). The anti-cancer effects of TQ on different cancers have been extensively studied. Nonetheless, only one paper in the entire National Center for Biotechnology Information (NCBI) database describes its effects on SCLC. A more detailed investigation is required. METHODS: The current study examined the impact of TQ in vitro on five SCLC cell lines and in vivo in a nude mouse xenograft model. The following in vitro effects of TQ on SCLC were evaluated: (a) cell viability; (b) apoptosis; (c) cell cycle arrest; (d) intracellular reactive oxygen species (ROS) levels, and (e) protein expression in concomitant signaling pathways. For the in vivo effects of TQ on SCLC, (a) tumor volume was measured, and (b) selected protein expression in selected concomitant signaling pathways was determined by Western blotting. RESULT: In general, TQ reduced cell viability, induced apoptosis and cell cycle arrest, depleted ROS, and altered protein expression in associated signaling pathways. Furthermore, TQ exhibited a tumor-suppressive effect in an H446 SCLC xenograft model. CONCLUSION: The cytotoxic impact of TQ arising from anti-cancer mechanisms was elucidated. The positive results obtained in this study warrant further investigation.

Nano-based formulations of thymoquinone are new approaches for psoriasis treatment: a literature review.

Psoriasis, a persistent immune-mediated inflammatory skin condition, affects approximately 2-3% of the global population. Current treatments for psoriasis are fraught with limitations, including adverse effects, high costs, and diminishing efficacy over time. Thymoquinone (TQ), derived from Nigella sativa seeds, exhibits promising anti-inflammatory, antioxidant, and immunomodulatory properties that could prove beneficial in managing psoriasis. However, TQ's hydrophobic nature and poor bioavailability have hindered its usefulness as a therapeutic agent. Recent research has strategically addressed these challenges by developing nano-thymoquinone (nano-TQ) formulations to enhance delivery and efficacy in treating psoriasis. Preclinical studies employing mouse models have demonstrated that nano-TQ effectively mitigates inflammation, erythema, scaling, epidermal thickness, and cytokine levels in psoriatic lesions. Various nano-TQ formulations, including nanoemulsions, lipid vesicles, nanostructured lipid carriers, and ethosomes, have been explored to improve solubility, facilitate skin penetration, ensure sustained release, and achieve site-specific targeting. Although clinical trials are currently scarce, the outcomes from in vitro and animal models are promising. The potential co-delivery of nano-TQ with other anti-psoriatic agents also presents avenues for further investigation.

[2, 6-dimethoxy-1, 4-benzoquinone alleviates septic shock in mice by inhibiting NLRP3 inflammasome activation].

OBJECTIVE: To investigate the mechanism of 2, 6-dimethoxy-1, 4-benzoquinone (DMQ), an active ingredients in fermented wheat germ extract, for inhibiting NLRP3 inflammasome activation and alleviating septic shock in mice. METHODS: Cultured murine bone marrow-derived macrophages (BMDM) stimulated with lipopolysaccharide (LPS) were treated with DMQ, followed by treatment with Nigericin, ATP, and MSU for activating the canonical NLRP3 inflammasome; the noncanonical NLRP3 inflammasome was activated by intracellular transfection of LPS, and AIM2 inflammasome was activated using Poly A: T.In human monocytic THP-1 cells, the effect of Nigericin on inflammasome activation products was examined using Western blotting and ELISA.Co-immunoprecipitation was performed to explore the mechanism of DMQ-induced blocking of NLRP3 inflammasome activation.In a male C57BL/6J mouse model of LPS-induced septic shock treated with 20 and 40 mg/kg DMQ, the levels of IL-1ß and TNF-α in the serum and peritoneal lavage fluid were determined using ELISA, and the survival time of the mice within 36 h was observed. RESULTS: Treatment with DMQ effectively inhibited LPS-induced activation of canonical NLRP3 inflammasome in mouse BMDM and human THP-1 cells and also inhibited non-canonical NLRP3 inflammasome activation in mouse BMDM, but produced no significant effect on AIM2 inflammasome activation.DMQ significantly blocked the binding between ASC and NLRP3.In the mouse models of septic shock, DMQ treatment significantly reduced the levels of IL-1ß in the serum and peritoneal fluid and obviously prolonged survival time of the mice. CONCLUSION: DMQ can effectively block ASC-NLRP3 interaction to inhibit NLRP3 inflammasome activation and alleviate LPSinduced septic shock in mice.

Identification and Analysis of Biomarkers Associated with Lipophagy and Therapeutic Agents for COVID-19.

BACKGROUND: Lipids, as a fundamental cell component, play an regulating role in controlling the different cellular biological processes involved in viral infections. A notable feature of coronavirus disease 2019 (COVID-19) is impaired lipid metabolism. The function of lipophagy-related genes in COVID-19 is unknown. The present study aimed to investigate biomarkers and drug targets associated with lipophagy and lipophagy-based therapeutic agents for COVID-19 through bioinformatics analysis. METHODS: Lipophagy-related biomarkers for COVID-19 were identified using machine learning algorithms such as random forest, Support Vector Machine-Recursive Feature Elimination, Generalized Linear Model, and Extreme Gradient Boosting in three COVID-19-associated GEO datasets: scRNA-seq (GSE145926) and bulk RNA-seq (GSE183533 and GSE190496). The cMAP database was searched for potential COVID-19 medications. RESULTS: The lipophagy pathway was downregulated, and the lipid droplet formation pathway was upregulated, resulting in impaired lipid metabolism. Seven lipophagy-related genes, including ACADVL, HYOU1, DAP, AUP1, PRXAB2, LSS, and PLIN2, were used as biomarkers and drug targets for COVID-19. Moreover, lipophagy may play a role in COVID-19 pathogenesis. As prospective drugs for treating COVID-19, seven potential downregulators (phenoxybenzamine, helveticoside, lanatoside C, geldanamycin, loperamide, pioglitazone, and trichostatin A) were discovered. These medication candidates showed remarkable binding energies against the seven biomarkers. CONCLUSIONS: The lipophagy-related genes ACADVL, HYOU1, DAP, AUP1, PRXAB2, LSS, and PLIN2 can be used as biomarkers and drug targets for COVID-19. Seven potential downregulators of these seven biomarkers may have therapeutic effects for treating COVID-19.

Ameliorative impacts of interleukin 35 or thymoquinone nanoparticles on lipopolysaccharide-induced renal injury in rats.

Interleukin-35 (IL-35) is a novel anti-inflammatory component, and its role in protecting against acute kidney disease (AKD) has not been explored. Thymoquinone (TQ) has been widely used for many therapeutic targets. Inflammation/oxidative signaling plays essential roles in the pathogenesis of diverse disorders, such as AKD, cancer, cardiac disease, aging, and metabolic and neurodegenerative disorders. The objective of the investigation was to evaluate how IL-35 prevents inflammation and oxidative stress indicators in the kidneys of rats caused by lipopolysaccharide (LPS). The experimental rats were allocated into six groups: control (0.5 mL saline); TQ (0.5 mg/kg, b.w. IP), IL-35 (100 µg of IL-35 /kg, b.w. IP), LPS (500 µg/kg b.w. IP), LPS + IL-35, and LPS + TQ. Results indicate that the hematological and blood biochemical parameters were substantially restored by TQ or IL-35 therapy. The elevation of kidney function (uric acid, creatinine, and cystatin C) and oxidative related biomarkers (MDA, PC, and MYO) in rat kidneys was significantly restored by the TQ and IL-35 therapies after LPS administration (P < 0.05). Serum immunological variables IgM and IgG were significantly restored by TQ and IL-35 in LPS-treated rats. Both IL-35 and TQ markedly mitigated the decrease antioxidant related biomarkers (SOD, GSH, CAT and TAC) triggered by LPS. The IL-35 and TQ treatments significantly diminished serum levels of inflammatory responses such as TNF-α, NF-κB, IL-6 and IFN-γ, and significantly increased IL-10 in LPS-treated rats. Additionally, serum levels of MCP, Caspase-3, andBcl-2 were significantly diminished by TQ or IL-35 therapy. The histopathology and immunohistochemistry for NF-kB, PCNA and TNF-α cytokines revealedremodeling when treated with TQ and IL-35. In summary, administration of IL-35 or TQ can attenuateLPS-induced renal damage by extenuatingoxidative stress, tissue impairment, apoptosis, and inflammation, implicating IL-35 as a promising therapeutic agent in acute-related renal injury.

Exploring MTH1 inhibitory potential of Thymoquinone and Baicalin for therapeutic targeting of breast cancer.

Cancers frequently have increased ROS levels due to disrupted redox balance, leading to oxidative DNA and protein damage, mutations, and apoptosis. The MTH1 protein plays a crucial role by sanitizing the oxidized dNTP pools. Hence, cancer cells rely on MTH1 to prevent the integration of oxidized dNTPs into DNA, preventing DNA damage and allowing cancer cell proliferation. We have discovered Thymoquinone (TQ) and Baicalin (BC) as inhibitors of MTH1 using combined docking and MD simulation approaches complemented by experimental validations via assessing binding affinity and enzyme inhibition. Docking and MD simulations studies revealed an efficient binding of TQ and BC to the active site pocket of the MTH1, and the resultant complexes are appreciably stable. Fluorescence measurements estimated a strong binding affinity of TQ and BC with Ka 3.4 ×106 and 1.0 ×105, respectively. Treating breast cancer cells with TQ and BC significantly inhibited the growth and proliferation (IC50 values 28.3 µM and 34.8 µM) and induced apoptosis. TQ and BC increased the ROS production in MCF7 cells, imposing substantial oxidative stress on cancer cells and leading to cell death. Finally, TQ and BC are proven strong MTH1 inhibitors, offering promising prospects for anti-cancer therapy.

Effects of thymoquinone in the lungs of rats against radiation-induced oxidative stress.

OBJECTIVE: Radiotherapy is an important treatment for a wide variety of malignancies, although many cancer patients who receive radiotherapy suffer from serious side effects during and after their treatment. Thymoquinone (TQ), the main active ingredient of Nigella sativa, has been reported to have various pharmacological properties, such as antioxidant, hepatoprotective, neuroprotective, antidiabetic, anti-inflammatory, nephroprotective, anticarcinogenic in many pharmacological and toxicological studies. In this study, we aimed to investigate whether there is a radioprotective effect of TQ on the lung tissue of rats exposed to ionizing radiation. MATERIALS AND METHODS: This study was designed as a prospective, placebo-controlled study. A total of 40 Sprague-Dawley rats were divided into four groups to test the radiation-protective effectiveness of TQ administered by intraperitoneal injection. Biochemical parameters were studied to assess the radiation-protective effects of TQ. RESULTS: Oxidative stress parameters, such as oxidative stress index (OSI), lipid hydroperoxide (LOOH) and total oxidant status (TOS), in lung tissue of the rats treated with TQ, were found to be lower than in received irradiation alone. Anti-oxidative parameters, such as total antioxidant status (TAS) level and paraoxonase (PON) activity, were statistically higher in the TR (IR plus TQ group) group compared with other groups. CONCLUSIONS: Findings show that TQ clearly protects lung tissue from radiation-induced oxidative stress and can be used as a radioprotective agent.

HSP90 Inhibition Attenuated Isoflurane-Induced Neurotoxicity in Mice and Human Neuroglioma Cells.

Isoflurane, a widely used inhalation anesthetic in clinical practice, is associated with an increased risk of neuronal injury. Heat shock protein 90 (HSP90) plays a crucial role in maintaining neuronal homeostasis under stress conditions; however, its role during isoflurane exposure remains poorly understood. In this study, we aimed to investigate the protective effects of HSP90 inhibition and explore the regulatory mechanisms underlying these effects during isoflurane exposure. We found that the HSP90 inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17 AAG) has great protective effects in mitigating isoflurane-induced ferroptosis of mouse hippocampus and cultured neuronal cells. We focused on the activity of the crucial protein GPX4 in ferroptosis and found that 17 AAG exerted protective effects, preserving the physiological GPX4 activity under isoflurane exposure; further, 17 AAG restored the protein level of GPX4. Further, we observed that the chaperone-mediated autophagy (CMA) pathway was activated; 17 AAG also mediated GPX4 degradation under isoflurane exposure. Additionally, it interfered with the formation of complexes between HSP90 and Lamp-2a, inhibiting CMA activity, followed by the blockade of GPX4 degradation, further affecting the isoflurane-induced ferroptosis. Based on these findings, we proposed HSP90 inhibition as a protective mechanism against isoflurane-induced ferroptosis in neurons.

Development of Two Novel One-Step and Green Microwell Spectrophotometric Methods for High-Throughput Determination of Ceritinib, a Potent Drug for Treatment of Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer.

Background and Objectives: Ceritinib (CER) is a potent drug of the third-generation tyrosine kinase inhibitor class. CER has been approved for the treatment of patients with non-small-cell lung cancer (NSCLC) harboring the anaplastic lymphoma kinase (ALK) mutation gene. In the literature, there is no green and high-throughput analytical method for the quantitation of CER in its dosage form (Zykadia® capsules). This study describes, for the first time, the development and validation of two novel one-step and green microwell spectrophotometric methods (MW-SPMs) for the high-throughput quantitation of CER in Zykadia® capsules. Materials and Methods: These two methods were based on an in microwell formation of colored derivatives upon the reaction of CER with two different benzoquinone reagents via two different mechanisms. These reagents were ortho-benzoquinone (OBQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and their reactions proceeded via condensation and charge transfer reactions, respectively. The reactions were carried out in 96-well transparent plates, and the absorbances of the colored reaction products were measured with an absorbance microplate reader at 540 and 460 nm for reactions with OBQ and DDQ, respectively. The optimum conditions of reactions were established, their molar ratios were determined, and reaction mechanisms were postulated. Under the refined optimum reaction conditions, procedures of MW-SPMs were established and validated according to the guidelines of the International Council on Harmonization. Results: The limits of quantitation were 6.5 and 10.2 µg/well for methods involving reactions with OBQ and DDQ, respectively. Both methods were applied with great reliability to the determination of CER content in Zykadia® capsules and their drug uniformity. Greenness of the MW-SPMs was evaluated using three different metric tools, and the results proved that the two methods fulfil the requirements of green analytical approaches. In addition, the simultaneous handling of a large number of samples with microvolumes in the proposed methods gave them the advantage of a high-throughput analysis. Conclusions: The two methods are valuable tools for rapid routine application in pharmaceutical quality control units for the quantitation of CER.

Thymoquinone Ameliorates Carfilzomib-Induced Renal Impairment by Modulating Oxidative Stress Markers, Inflammatory/Apoptotic Mediators, and Augmenting Nrf2 in Rats.

Chemotherapy-induced kidney damage is an emerging problem that restricts cancer treatment effectiveness. The proteasome inhibitor carfilzomib (CFZ) is primarily used to treat multiple myeloma and has been associated with severe renal injury in humans. CFZ-induced nephrotoxicity remains an unmet medical need, and there is an urgent need to find and develop a nephroprotective and antioxidant therapy for this condition. Thymoquinone (TQ) is a bioactive compound that has been isolated from Nigella sativa seeds. It has a wide range of pharmacological properties. Therefore, this experimental design aimed to study the effectiveness of TQ against CFZ-induced renal toxicity in rats. The first group of rats was a normal control (CNT); the second group received CFZ (4 mg/kg b.w.); the third and fourth groups received TQ (10 and 20 mg/kg b.w.) 2 h before receiving CFZ; the fifth group received only TQ (20 mg/kg b.w.). This experiment was conducted for 16 days, and at the end of the experiment, blood samples and kidney tissue were collected for biochemical assays. The results indicated that administration of CFZ significantly enhanced serum marker levels such as BUN, creatinine, and uric acid in the CFZ group. Similarly, it was also noticed that CFZ administration induced oxidative stress by reducing antioxidants (GSH) and antioxidant enzymes (CAT and SOD) and increasing lipid peroxidation. CFZ treatment also enhanced the expression of IL-1ß, IL-6, and TNF-α production. Moreover, CFZ increased caspase-3 concentrations and reduced Nrf2 expression in the CFZ-administered group. However, treatment with 10 and 20 mg/kg TQ significantly decreased serum markers and increased antioxidant enzymes. TQ treatment considerably reduced IL-1ß, IL-6, TNF-α, and caspase-3 concentrations. Overall, this biochemical estimation was also supported by histopathological outcomes. This study revealed that TQ administration significantly mitigated the negative effects of CFZ treatment on Nrf2 expression. Thus, it indicates that TQ may have utility as a potential drug to prevent CFZ-induced nephrotoxicity in the future.

Design, Synthesis, and Acute Toxicity Assays for Novel Thymoquinone Derivative TQFL12 in Mice and the Mechanism of Resistance to Toxicity.

TQFL12 is a novel derivative designed and synthesized on the basis of Thymoquinone (TQ) which is extracted from Nigella sativa seeds. We have demonstrated that TQFL12 was more effective in the treatment of TNBC than TQ. In order to directly reflect the acute toxicity of TQFL12 in vivo, in this study, we designed, synthesized, and compared it with TQ. The mice were administered drugs with different concentration gradients intraperitoneally, and death was observed within one week. The 24 h median lethal dose (LD50) of TQ was calculated to be 33.758 mg/kg, while that of TQFL12 on the 7th day was 81.405 mg/kg, and the toxicity was significantly lower than that of TQ. The liver and kidney tissues of the dead mice were observed by H&E staining. The kidneys of the TQ group had more severe renal damage, while the degree of the changes in the TQFL12 group was obviously less than that in the TQ group. Western blotting results showed that the expressions of phosphorylated levels of adenylate-activated protein kinase AMPKα were significantly up-regulated in the kidneys of the TQFL12 group. Therefore, it can be concluded that the acute toxicity of TQFL12 in vivo is significantly lower than that of TQ, and its anti-toxicity mechanism may be carried out through the AMPK signaling pathway, which has a good prospect for drug development.

Anticancer activity of thymoquinone against breast cancer cells: Mechanisms of action and delivery approaches.

The rising incidence of breast cancer has been a significant source of concern in the medical community. Regarding the adverse effects and consequences of current treatments, cancers' health, and socio-economical aspects have become more complicated, leaving research aimed at improved or new treatments on top priority. Medicinal herbs contain multitarget compounds that can control cancer development and advancement. Owing to Nigella Sativa's elements, it can treat many disorders. Thymoquinone (TQ) is a natural chemical derived from the black seeds of Nigella sativa Linn proved to have anti-cancer and anti-inflammatory properties. TQ interferes in a broad spectrum of tumorigenic procedures and inhibits carcinogenesis, malignant development, invasion, migration, and angiogenesis owing to its multitargeting ability. It effectively facilitates miR-34a up-regulation, regulates the p53-dependent pathway, and suppresses Rac1 expression. TQ promotes apoptosis and controls the expression of pro- and anti-apoptotic genes. It has also been shown to diminish the phosphorylation of NF-B and IKK and decrease the metastasis and ERK1/2 and PI3K activity. We discuss TQ's cytotoxic effects for breast cancer treatment with a deep look at the relevant stimulatory or inhibitory signaling pathways. This review discusses the various forms of polymeric and non-polymeric nanocarriers (NC) and the encapsulation of TQ for increasing oral bioavailability and enhanced in vitro and in vivo efficacy of TQ-combined treatment with different chemotherapeutic agents against various breast cancer cell lines. This study can be useful to a broad scientific community, comprising pharmaceutical and biological scientists, as well as clinical investigators.

KRAS Mutation Reduces Thymoquinone Anticancer Effects on Viability of Cells and Apoptosis.

BACKGROUND: Cancer is a life-threatening condition with an economic burden on societies. Phytotherapy is rapidly taking place in cancer research to increase the success of treatment and quality of life. Thymoquinone (TQ) is the main active phenolic compound obtained from the essential oil of the Nigella sativa (black cumin) plant seed. For a long time, black cumin has been used traditionally for the remedy of different diseases because of its various biological effects. It has been shown that most of these effects of black cumin seeds are due to TQ. TQ became a popular research topic for phytotherapy studies for its potential therapeutic applications, and more research is going on to fully understand its mechanisms of action, safety, and efficacy in humans. KRAS is a gene that regulates cell division and growth. Monoallelic variants in KRAS result in uncontrollable cell division, leading to cancer development. Studies have shown that cancer cells with KRAS mutations are often resistant to certain types of chemotherapy and targeted therapies. OBJECTIVE: This study aimed to compare the effect of TQ on cancer cells with and without KRAS mutation to better understand the reason why TQ may have different anticancer effects in the different types of cancer cells. METHODS: TQ was investigated for its cytotoxic and apoptotic effects in laryngeal cancer cells (HEp-2) without KRAS mutation and compared to mutant KRAS-transfected larynx cancer cells and KRAS mutation-carrying lung cancer cells (A549). RESULTS: We showed that TQ has more cytotoxic and apoptotic effects on laryngeal cancer cells without KRAS mutation than in cells with mutation. CONCLUSION: KRAS mutations decrease the effect of TQ on cell viability and apoptosis, and further studies are needed to fully understand the relationship between KRAS mutations and thymoquinone effectiveness in cancer treatment.

Thymoquinone enhanced the antitumor activity of cisplatin in human bladder cancer 5637 cells in vitro.

PURPOSE: Cisplatin-based chemotherapy is a primary alternative for treating bladder cancer. But drug resistance and various side effects are the main unsightliness challenges. In search of a novel chemotherapeutic approach, this study was conducted to investigate whether thymoquinone (TQ) chemosensitize 5637 bladder cancer cells to cisplatin (CDDP). METHODS: The IC50 for each drug was first determined. The cells were then pre-exposed to 40 µM of TQ for 24 h before being treated with 6 µM of cisplatin. The viability and the sub-G1 population of the 5673 cells were respectively evaluated by alamar blue assay and propidium iodide staining. RT-qPCR was also applied to analyze the expression profile of the apoptosis-related genes (Bax, Bcl-2, p53). RESULTS: The viability of the cells treated with the combination of TQ and CDDP was significantly decreased compared to CDDP- or TQ-treated cells. TQ at the concentration of 40 µM increased the cytotoxicity of 6 µM CDDP by 35.5%. Moreover, flow cytometry analysis indicated that TQ pre-treatment of the cells resulted in a 55.5% increase in the population of 5637 cells in the sub-G1 phase compared to cells treated with CDDP alone. The results from RT-qPCR exhibited that the exposure of the cells to both TQ and CDDP significantly elevated Bax/Bcl-2 ratio by down-regulating Bcl-2 expression. CONCLUSION: TQ significantly increased the cytotoxicity of CDDP in 5637 cells and induced apoptosis by down-regulation of the Bcl-2. Therefore, TQ and CDDP might be an effective therapeutic combination for TCC bladder cancer treatment.

Molecular mechanisms and signaling pathways of black cumin (Nigella sativa) and its active constituent, thymoquinone: a review.

BACKGROUND: Nigella sativa and its main bioactive ingredient, thymoquinone, exhibit various pharmacological activities, including neuroprotective, nephroprotective, cardioprotective, gastroprotective, hepatoprotective, and anti-cancer effects. Many studies have been conducted trying to elucidate the molecular signaling pathways that mediate these diverse pharmacological properties of N. sativa and thymoquinone. Accordingly, the goal of this review is to show the effects of N. sativa and thymoquinone on different cell signaling pathways. METHODS: The online databases Scopus, PubMed and Web of Science were searched to identify relevant articles using a list of related keywords such as Nigella sativa, black cumin, thymoquinone, black seed, signal transduction, cell signaling, antioxidant, Nrf2, NF-κB, PI3K/AKT, apoptosis, JAK/STAT, AMPK, MAPK, etc. Only articles published in the English language until May 2022 were included in the present review article. RESULTS: Studies indicate that N. sativa and thymoquinone improve antioxidant enzyme activities, effectively scavenges free radicals, and thus protect cells from oxidative stress. They can also regulate responses to oxidative stress and inflammation via Nrf2 and NF-κB pathways. N. sativa and thymoquinone can inhibit cancer cell proliferation through disruption of the PI3K/AKT pathway by upregulating phosphatase and tensin homolog. Thymoquinone can modulate reactive oxygen species levels in tumor cells, arrest the cell cycle in the G2/M phase as well as affect molecular targets including p53, STAT3 and trigger the mitochondrial apoptosis pathway. Thymoquinone, by adjusting AMPK, can regulate cellular metabolism and energy hemostasis. Finally, N. sativa and thymoquinone can elevate brain GABA content, and thus it may ameliorate epilepsy. CONCLUSIONS: Taken together, the improvement of antioxidant status and prevention of inflammatory process by modulating the Nrf2 and NF-κB signaling and inhibition of cancer cell proliferation through disruption of the PI3K/AKT pathway appear to be the main mechanisms involved in different pharmacological properties of N. sativa and thymoquinone.

Combinatorial Chemosensitive Nanomedicine Approach for the Treatment of Breast Cancer.

Breast cancer is the most commonly diagnosed type of cancer and ranks second among cancer that leads to death. From becoming the foremost reason for global concern, this multifactorial disease is being treated by conventional chemotherapies that are associated with severe side effects, with chemoresistance being the ruling reason. Exemestane, an aromatase inhibitor that has been approved by the US FDA for the treatment of breast cancer in post-menopausal women, acts by inhibiting the aromatase enzyme, in turn, inhibiting the production of estrogen. However, the clinical application of exemestane remains limited due to its poor aqueous solubility and low oral bioavailability. Furthermore, the treatment regimen of exemestane often leads to thinning of bone mineral density. Thymoquinone, a natural compound derived from the oil of the seeds of Nigella sativa Linn, possesses the dual property of being a chemosensitizer and chemotherapeutic agent. In addition, it has been found to exhibit potent bone protection properties, as evidenced by several studies. To mitigate the limitations associated with exemestane and to deliver to the cancerous cells overcoming chemoresistance, the present hypothesis has been put forth, wherein a natural chemosensitizer and chemotherapeutic agent thymoquinone will be incorporated into a lipid nanocarrier along with exemestane for combinatorial delivery to cancer cells. Additionally, thymoquinone being bone protecting will help in ousting the untoward effect of exemestane at the same time delivering it to the required malignant cells, safeguarding the healthy cells, reducing the offsite toxicity, and providing potent synergistic action.

Hepatic Response to the Interaction Between Thymoquinone and Iron-Dextran: an In Vitro and In Vivo Study.

Iron is one of the most important essential elements for cell function. However, iron overload can exert destructive effects on various tissues, especially the liver. The present study was designed to evaluate the effect of thymoquinone (TQ) on hepatotoxicity induced by iron-overload in in vitro and mouse model. After in vitro studies, thirty mice were divided into five groups, six each. Group 1 received normal saline. Group 2 received five doses of iron dextran (i.p; 100 mg/kg, one dose every 2 days). Group 3 received TQ (orally, 2 mg/kg/day). Groups 4 and 5 were administrated iron dextran saline (i.p; 100 mg/kg, one dose every 2 days) following treatment with 0.5 and 2 mg/kg/day of TQ, respectively. Based on the findings of the DPPH experiment, although TQ has significant anti-radical potential, at a safe dose of 15 × 10+3 nM, it reduced the IC50 of iron dextran on HepG2 cells by about 25%, in in vitro. Following administration of low-dose TQ (0.5 mg/kg), a significant improvement was observed in serum hepatic enzymes activity and hepatic lipid peroxidation compared to iron dextran. However, administration of TQ-high dose (2 mg/kg) led to decrease antioxidant defense alongside increased serum hepatic enzymes and pathological damages in iron dextran-treated animals. Due to the different efficacy of TQ in treatment groups, it seems that the TQ therapeutic index is low and does not have significant safety in the iron overload status.

Effect of thymoquinone on pharmacokinetics of 5-fluorouracil in rats and its effect on human cell line in vitro.

Thymoquinone (TQ) is one of the components extracted from Nigella sativa seeds and has antioxidant, anti-inflammatory, and anticancer effects. We evaluated the effect of TQ on 5-fluorouracil (5-FU) pharmacokinetics (PK) in vivo and in vitro on human colorectal cancer cell line. Ten Adult male Wistar rats were assigned to two groups. TQ treated group received intraperitoneal TQ once daily for 14 consecutive days (5 mg/kg). Both groups received intraperitoneal 5-FU (50 mg/kg) on day 15 and blood samples were collected from retro-orbital plexus. The pharmacokinetics parameters were analyzed using high-performance liquid chromatography (HPLC). Moreover, various concentrations of 5-FU, TQ, and combination of 5-FU and TQ were added to the HT-29 cell line and cell viability was measured using 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay. The maximum serum concentration (Cmax), area under the curve (AUC), and time of maximum concentration (Tmax) of 5-FU in TQ treated group were significantly increased approximately by 61, 60, and 24% compared to the control group, respectively. The combination of 5-FU with TQ (0.284 mM) showed a greater inhibitory effect on HT-29 cell growth compared to the alone 5-FU (0.027 and 0.055 mM) administration. TQ increases the AUC, Cmax, and Tmax of 5-FU and has a synergistic effect on the PK of 5-FU. Moreover, low concentration of TQ enhances the inhibitory effects of 5-FU on cell growth in colorectal cancer cell line. This synergistic effect might enhance the anticancer effects of low concentration of 5-FU, leading to drug dose reduction and reduced systemic toxicity of this chemotherapeutic agent.